METHOD OF PREPARING POLYTETRAFLUOROETHYLENE Russian patent published in 2001 - IPC

FIELD: preparation of polytetrafluoroethylene by polymerization of tetrafluoroethylene. SUBSTANCE: method comprises purging reactor with inert gas to oxygen content of 0.01-0.05 %, purifying water for polymerization to remove organic and inorganic impurities by filtration through two successively disposed inverted osmotic membranes located so that 25-50% of stream with concentrated admixtures being admitted from space above first membrane and 20- 50 of stream with concentrated impurities being admitted from space above second membrane with said stream recycled to first membrane. Process of admitting tetrafluoroethylene for polymerization is carried out at rate which maintains temperature in gas phase of reactors at 40-60 C. Tetrafluoroethylene to be polymerized contains 0.05-0.4 mg of alkylamine per liter of gaseous tetrafluoroethylene. Alkylamine includes tertiary alkylamines from group of triethyl- tripropyl-or tributylamines. Method makes it possible to increase safety of process and yield of polymer and reduced consumption of initiating system. EFFECT: more efficient preparation method. 5 cl, 1 dwg, 4 tbl